Iran's oil minister says the fighting between Iraqi troops and Islamic State militants will delay the planned start of natural gas exports to neighboring Iraq.

Bijan Zanganeh is quoted on the ministry's official website on Wednesday as saying that the "upheaval in Iraq is postponing the exports."

The pipeline, which is still under construction on the Iraqi side, goes partly through territory controlled by the Islamic State group.

Pipeline workers, mainly Iranians, have come under attack several times, especially in Diyala province, which has disrupted work.

It's unclear when the new gas pipeline will be finished or when it will go on line.

Under a 2012 agreement, Iran was to start exporting gas to Iraq in 2014 through the new pipeline, which is to feed three power plants in Iraq.